Method of making paper



W. P. ARGY METHOD OF MAKING PAPER Dec. 15, 1931.

Filed'March '7, 1930 2 Sheets-Sheet 1 @TTY.

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' Dec. 15, 1931.

w. P. ARGY METHOD OF MAKING PAPER Filed March 7, 1950 2 Sheets-Sheet 2 lwveu-ro a;

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Patented Dec. 15, 1931 I UNITED STATES PATENT OFFICE Application filed March 7,

This invention relates to a method of making paper.

The object of the invention is to provide a novel method of making paper involving the pre-heatingof the paper web during its manufacture prior to its passage through the last set of the wet press rolls of the paper machine and by which the pre-h eating operation may be conducted in such manner as to produce superior paper than has heretofore been possible by other methods of which I am aware.

With this object in view, the invention con-. sists in the method of making paper hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings, Fig. 1 is a side elevation of the wet end of a paper making machine illustrating one form of apparatus for practicing the present process; Fig. 2 is a' detail in front elevation illustrating the mechanism for controlling the temperature of the preheating roll, and Fig. 3 is a diagrammatic view illustrative of .an alternate form of apparatus for practicing the process.

The present method of making paper involves the preheating of the paper web during its passagethrough the wet pressing apparatus to diminish the surface tension of the water within the web so that it is possible to remove by mechanical pressure a relatively large amount of water. Pre-heating apparatus for paper machines have heretofore been proposed and successfully used, as for example the apparatus illustrated in the following United States patents: Robert Edward Argy, No, 1,712,374; Robert Edward Argy, No. 1,712,375; John C. Corcoran, No. 1,690,402. In the use of such pre-heating apparatus, and in the manufacture of paper in accordance with the methods disclosed in such prior patents, I have found that by maintaining the temperature at which the web of paper is pre-heated between very definite limits, diminution in the strength of the paper which at times was experienced may be avoided. In addition paper of higher quality and grade may be made and at the same time a maximum efiiciency obtained in 1980. Serial No. 433,983.

the mechanical expression of water by the wet pressing apparatus Accordingly, the present invention contemplates a method of making paper in which the paper is pre-heated between defi- 66 nite limits of temperature, preferably 100 to 105 F., and it has been found that in those instances where the pre-heating operation has been conducted to heat the paper web to above 105 at the point in the manufacture of the paper where the web enters the last wet presses, the sizing used in the manufacture of the paper is caused to melt to acertain extent with an accompanying loss of the same and an accompanying loss of its 5 effectiveness resulting in the loss of strength of the paper or a diminution in the so-called Mullen pop test. It has also been found from experience that when the temperature of the web has been raised during the pre-heating operation above 100 F. considerable fuzz accumulates on the pre-heating roll presumably caused by the sizing in the paper melting and sticking to the roll and drawing with it a film of the stock fiber, and as a result the paper becomes pitted and damaged diminishing the value of the same, and this condition detracts considerably from the utility of the pre-heating process in the production of fine paperssuch as bonds, ledgers and book fpapers.

Re erring now to the drawings, and articularly to Fig. 1, 10 represents the we 0f paper in the condition in which it exists after having been formed in the usual way and is 95 being conducted to the first presses of the wet pressing apparatus. The paper web during its passage through the press rolls 12, 14 comprising the first presses is supported upon the usual form of felt 15 and a portion of the water is extracted by the press rolls 12,

14. Thereafter the web isconducted from the first presses toward the second presses down to a point adjacent one of the felt carrying rolls 16 and thence aroundthe usual paper guide roll 17 from which it is conducted around .the baby drier 20 by which it is pre-heated, and thence through a second set of Wet press rolls 22, 24 and around the usual guide roll'26 and over a guide roll 28, mo

and thence around the successive steamheated drums of the usual set of drying cylinders which perform the final drying operation. 7

The baby drier 20 is arranged to be driven in the direction of the arrow 31 reverse to its normal direction of rotation and preferably at a speed synchronized with respect to the speed of the second set of wet press rolls 22, 24 so as to maintain the web in an even and smooth condition during its passage over the baby drier and through the wet press rolls. The apparatus as thus far described comprises that illustrated in and forming the subject matter of the patent to Robert Edward Argy No. 1,712,374, May 7, 1929. In accordance with the present method, the preheating of the paper Web is so controlled that the Web enters the wet presses at a temperature just below that at which the strength of the paper would be impaired, preferably between 100 and 105 F. In order to control the temperature at which the paper web is heated during its passage over the baby drier 20, the steam supplied to the baby drier 20 is controlled, preferably in an automatic manner, to supply suflicient heat to the web through the medium of the baby drier so that and be sure that the temperature to which the the temperature is maintained between the limits of 100 and 105 F., in order that the maximum efficiency may be obtained in the mechanical expression of the water by means of the last set of wet presses 22, 24, and at the same time so that the size within the paper isv not over-heated and the accompanying troubles which have heretofore been experienced may be eliminated.

Referring now particularly to Fig. 2, one form of apparatus is shown which may be used in order to maintain the temperature of the web passing over the pre-heating roll within the desired limits of 100 and 105 F. including a controller bulb or thermostatic element 38 of any usual or preferred form positioned within the discharge pipe 40 through which the outlet water from the preheating roll is discharged. The thermostatic element is connected with a regulating valve 48 which also may be of known construction arranged to increase and decrease the flow of steam being supplied from the steam line 50 to the inlet side of the pre-heating roll. The regulating Valve 48 is preferably set so as to operate to start and cut off the steam supply to the pro-heating roll when the thermostatic element 38 indicates that the pre-heating roll has reached either temperature limit such as 100 F. or 105 F, and the regulating valve 18 may be calibrated so that an operator may set the regulator for a given weight of paper web will be heated during passage over the pre-heating roll will be maintained within any desired range of temperature, such as 100 to 105 F. In those instances where heavier or lighter papers are run, the operator will set the regulator accordingly so that it will automatically supply the requisite quantity of steam to maintain the web temperature between 100 and 105 F.

In Fig. 3 I have illustrated an alternate form of apparatus for pre-heating the paper web prior to its passage through the last set of rolls of the wet pressing apparatus, and in accordance with the present invention the upper roll of the two felt carrying rolls 60, 61 around which the paper web is conducted to be pre-heated, is provided with the control apparatus illustrated in Fig. 2, in order that the temperature to which the web is pre-heated may be controlled between the limits of 100 and 105 F.

While the preferred apparatus for practicing the present process'has been herein illustrated and described, it will be understood that other forms of apparatus may be employed to practice the method within the scope of the following claims.

Having thus described the invention what is claimed is 1. In the method of making paper, the steps which comprise passing the paper web over a pre-heating roll prior to its passage through the last set of wet presses, and maintaining the temperature to which the web is Q5 heated by the roll between the limits of and F.

2. In the method of making paper, the steps which comprise subjecting the paper web to pre-heating prior to its passage through the last set of wet press rolls, and maintaining the temperature to which the web is pre-heated between the limits of 100 and 105 F..

In testimony whereof I have signed my name to this specification.

WILLIAM P. ARGY. 

